Wnt3a promotes differentiation of human bone marrow-derived mesenchymal stem cells into cementoblast-like cells.

Cementum is a calcified, avascular connective tissue that laminates the root of a tooth and plays a pivotal role in the development, homeostasis, and regeneration of a periodontal tissue. As a potential treatment for periodontal tissue defects in the patient with chronic periodontitis, much attention has been paid to tissue engineering combined with mesenchymal stem cells for regenerating periodontal tissues including cementum. However, limited information is available for the molecular factors that have impacts on the differentiation of mesenchymal stem cells into cementoblasts. Here, we focus on the effect of Wnt3a as a potential inducer and tested the effect of this protein in vitro using human bone marrow-derived mesenchymal stem cells. It was found that, when cells were cultured in an osteogenic medium containing Wnt3a, cementoblast-specific genes, such as cementum protein 1 and cementum attachment protein, as well as bone-related genes were significantly upregulated. These results suggest that Wnt3a promotes differentiation of the cells into cementoblast-like cells. Further experiments were carried out using inhibitors to gain deeper insights into molecular mechanisms underlying the observed differentiation. As a result, we conclude that Wnt3a-triggered differentiation into cementoblast-like cells is the consequence of the activation of the canonical Wnt signaling pathway with possible involvement of the non-canonical pathway.